Machines and methods for manufacturing ropes, in particular steel cords

ABSTRACT

Apparatus and method of manufacturing rope or cord wherein a double-twisting device is used in conjunction with an equalizer in a single apparatus to provide rope or steel cord of the equiverse type.

United States Patent 11 1 Maderna Nov. 27, 1973 MACHINES AND METHODS FOR [56] References Cited MANUFACTURING ROPES, 1N UNITED STATES PATENTS PARTICULAR STEEL CORDS 3,585,792 6/1971 Hofrichter 57/5852 [75] Inventor: Michele L, Maderna, Monza, Italy 3,726,074 4/1973 Peene 57/5834 [73] Assignee: lntlustrie Pirelli S.p.A., Milano, Italy FOREIGN PATENTS OR APPLICATIONS 22 Filed; Nov. 19 19 1 1,360,663 3/1964 France 57/5852 [21] Appl' 200,338 Primary ExaminerJohn Petrakes Att0rneyRichard K. Stevens et al.

[30] Foreign Application Priority Data Dec. 4, 1970 Italy 32630 A/7O ABSTRACT Apparatus and method of manufacturing rope or cord [52] US. Cl. 57/5852, 57/166 wherein a doublatwistingydevice is used in C0njunc [51] Int. Cl D07b 3/12 tion with an equalizer i a single apparatus to provide [58] Field of Search 57/58.49, 58.52, rope or Steel cord of the equiverse type 4 Claims, 1 Drawing Figure MACHINES AND METHODS FOR MANUFACTURING ROPES, IN PARTICULAR I STEEL CORDS The present invention relates to a method and a machine of new type for the speedy and cheap manufacture of ropes, in particular steel cords, of the equiverse type, for example like those used as reinforcements in the manufacture of pneumatic tires. The cords of the equiverse" type are those in which the strands have the same winding sense as the single elementary wires constituting them.

As known, such cords are at present manufactured in two phases, carried out on two different machines. In the first phase the elementary wires are joined together usually by subjecting them to a double twist, in order to obtain perfectly balanced strands, on a doubletwisting" machine.

In a widely used double-twisting machine, the various elementary wires are paid off from as many spools (placed on swinging supports provided inside a rotating cylinder), then they are brought on the outer surface of the cylinder, are moved away to one end of the latter along one of its generatrices, are transferred as far as the generatrix of the cylinder which is diametrically opposite to the preceding one, and at last are transferred,

along this second generatrix, to a roller situated in proximity of the second end of the cylinder, from which they pass to a collecting drum, sometimes, preceded by a capstan.

In this way, each elementary wire is subjected to a first twist (cabling) between the feeding spool and the rotating cylinder, and to a second twist (stranding) in the same sense as the first, between the rotating cylinder and the fixed roller. The second phase of the present manufacture of the cords comprises joining together the several strands 50 obtained by means of a stranding machine, which can also be of the doubletwisting type.

The object of this invention is to simplify the manufacture of cords of the equiverse type by reducing the number of required machines and by working according to a simpler method, with the result of obtaining a higher output and therefore a less expensive product.

Accordingly, the present invention relates to a method for manufacturing ropes, in particular steel cords of the equiverse type, which comprises winding up on a plurality of spools, corresponding to the number of rope strands to be obtained, as many groups of elementary wires parallel to one another, not twisted and in a number equal to that of the wires of each strand, characterized in that it comprises the following further steps, carried out continuously on a single machine of the so-called double-twisting type:

placing the spools on conventional swinging supports inside the rotating cylinder of the machine;

imparting a cabling, simultaneously and separately, to each group of elementary wires in order to obtain a number of strands equal to the number of said groups of wires;

guiding all of the strands together for a certain travel to form a bundle of strands parallel to one another;

forming the rope by imparting to said bundle of strands a stranding which, having the same sense as the cabling, constitutes a second twist for each of the single elementary wires;

dragging the rope in a conventional manner through an equalizer as far as acollecting device.

The present invention deals also with an improvement of the so-called double-twisting machine, so that it can carry out simultaneously the cabling and the stranding.

The invention will be better understood with reference to the attached FIGURE which represents 'diagrammatically the double-twisting machine, and with reference to the following description, which refers to an exemplary embodiment which is not intended to be limiting. lt isto be understood that, in the present specification, the word strand indicates the joining of a certain number of helically wound wires (made of steel or of another material) irrespective of the number of such wires, provided that said number is not smaller than two.

The FIGURE shows spools I, 2, 3 swinging on appropriate supports (not illustrated) inside a cylinder 4, which is placed into rotation with known means (also not illustrated). Each spool carries, wound about it, one group of steel wires, untwisted and parallel to one another. Each group of wires 5, 6, 7 is conveyed from spools l, 2, 3 as far as the outer surface of cylinder 4. During said travel, the groups of wires pass through devices la, 2a, 3a intended to prevent backtwisting or untwisting, through bushingsv 1b, 2b, 3b arranged along the axis of cylinder 4 and through bushings 1c, 20, 3c arranged on the surface of the latter. By virtue of the rotation of cylinder 4 with respect to spools 1, 2, 3, each group of wires is subjected to an individual but simultaneous cabling. In this way each group of wires forms a strand (respectively indicated as 5a, 6a, 7a), i.e., the strands are as many as the spools in the machine. These strands constitute a bundle of strands which are guided, in parallel relationship with one another, at first along the outer surface of cylinder 4 to the eyelet 8, and then as far as roller 9.

The axis of roller 9 is perpendicular to that of cylinder 4; moreover said roller rotates together with said cylinder 4.

The bundle of strands 13 is subjected to a stranding, from roller 9 onwards, because it passes through the eyelets l0, 11, also provided on the outer surface of cylinder 4, and then passes through bushing 12, whose axis is parallel to the axis of cylinder 4, but is fixed with respect to the latter. This stranding is characterized in that it is a second twisting, having the same sense as the cabling, imparted to each of the wires constituting the strands. The cord so formed passes through an equalizer l5 and a capstan 16 as is already known, and is then guided and wound up about a drum 17. The equalizer 15, about the pulleys of which the cord 14 is compelled to follow a travel in the figure of a complete eight, is kept in rotation with means not illustrated. In this way, a certain number of twists per meter is imparted to the cord, which is sufficient to make it inert. For clarity, the strands constituting bundle 13 are represented as separate from one another; actually they are parallel and closely adjacent.

It is evident that a considerable saving can be obtained by using this double-twisting machine which needs only simple auxiliary equipment to wind up the elementary metallic wires in parallel relationship on the spools before placing the latter on the swinging supports positioned inside the rotating cylinder. Obviously, the rotational speed of the latter and the speed at which the produced cord is wound up on the collecting drum are chosen in such a way that the single wires on one hand and the various strands on the other will receive the total number of twists per meter which is considered necessary for achieving an optimum performance of the cord in service, for example, the desired per cent stretch, if it is used for the manufacture of pneumatic tires.

The present invvention includes also any modification accessible to a technician of the art and deriving from the above indicated inventive principles For instance, bushings lc, 21:, 3c can be arranged along several generatrices of the rotating cylinder 4, instead of being arranged along only one generatrix, as shown in the FIGURE.

What is claimed is:

I. An apparatus for making a cord of the equiverse type comprising a plurality of spools for winding a plurality of wires in parallel relationship thereabout;

a cylinder disposed about said spools and adapted to be rotated thereabout; said cylinder having a separate opening in its sidewall for passage of each group of wires from each spool to the outside of the cylinder;

means adjacent to each spool for looping the wires as they are unwound from the spool and means for guiding the resulting strand of twisted wires from the looping means through one of said openings;

means carried externally by the cylinder for guiding the strands and orienting them into a bundle of parallel strands;

a bushing having its axis parallel to that of the cylinder but which is stationary with respect to the cylinder for guiding the strands as they are twisted once about each other from the rotating cylinder, an equalizer downstream of the said bushing; and means for winding the resulting cord.

2. The apparatus of claim 1 wherein said means for guiding the wires from the looping means through one of said openings is a first bushing having its axis parallel to the longitudinal axis of the cylinder and a second bushing in the opening; the means for guiding and orienting the strands carried externally by the cylinder are a pair of 'circumferentially spaced bushings adjacent to one end of the cylinder, a roller carried by the cylinder at a first end thereof and disposed between the said spaced bushings having its axis perpendicular with the longitudinal axis of the cylinder; the said stationary bushing is disposed at a second end of the cylinder, an equalizer, a capstan and a drum for winding the resulting cord thereabout are disposed in that order downstream of the stationary bushing.

3. A method for forming a cord having a plurality of wire twisted once to form a strand and a plurality of the strands are twisted once in the same sense as the wires are twisted which comprises unwinding a plurality of wires disposed in parallel relationship on a spool, guiding the wires through the sidewall of a cylinder rotating about the spool, disposing the resulting once twisted wires as strands in parallel relationship to form a bundle thereof and passing the strands through a guide means stationary with respect to the cylinder whereby the strands are twisted once into a cord.

4. The method of claim 3 wherein the twisted strands are passed through an equalizer, a capstan and wound 

1. An apparatus for making a cord of the equiverse type comprising a plurality of spools for winding a plurality of wires in parallel relationship thereabout; a cylinder disposed about said spools and adapted to be rotated thereabout; said cylinder having a separate opening in its sidewall for passage of each group of wires from each spool to the outside of the cylinder; means adjacent to each spool for looping the wires as they are unwound from the spool and means for guiding the resulting strand of twisted wires from the looping means through one of said openings; means carried externally by the cylinder for guiding the strands and orienting them into a bundle of parallel strands; a bushing having its axis parallel to that of the cylinder but which is stationary with respect to the cylinder for guiding the strands as they are twisted once about each other from the rotating cylinder, an equalizer downstream of the said bushing; and means for winding the resulting cord.
 2. The apparatus of claim 1 wherein said means for guiding the wires from the looping means through one of said openings is a first bushing having its axis parallel to the longitudinal axis of the cylinder and a second bushing in the opening; the means for guiding and orienting the strands carried externally by the cylinder are a pair of circumferentially spaced bushings adjacent to one end of the cylinder, a roller carried by the cylinder at a first end thereof and disposed between the said spaced bushings having its axis perpendicular with the longitudinal axis of the cylinder; the said stationary bushing is disposed at a second end of the cylinder, an equalizer, a capstan and a drum for winding the resulting cord thereabout are disposed in that order downstream of the stationary bushing.
 3. A method for forming a cord having a plurality of wire twisted once to form a strand and a plurality of the strands are twisted once in the same sense as the wires are twisted which comprises unwinding a plurality of wires disposed in parallel relationship on a spool, guiding the wires through the sidewall of a cylinder rotating about the spool, disposing the resulting once twisted wires as strands in parallel relationship to form a bundle thereof and passing the strands through a guide means stationary with respect to the cylinder whereby the strands are twisted once into a cord.
 4. The method of claim 3 wherein the twisted strands are passed through an equalizer, a capstan and wound on a spool. 